useful.dk is a .dk domain served by 2 nameservers (duke.ns.cloudflare.com, keyla.ns.cloudflare.com). It was registered on 23 April 2003 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Its website address 104.21.54.126 is hosted by Cloudflare, Inc. (AS13335). Mail is handled by aspmx.l.google.com, alt1.aspmx.l.google.com and 3 more. The zone is DNSSEC-signed and validates, publishes a DMARC policy and is reachable over IPv6. Below are all of its DNS records from our latest scan: nameservers, A/AAAA, MX, TXT, SPF, DMARC, CAA, TLSA/DANE, MTA-STS, SRV and more.
| IP | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 104.21.54.126 | 300s | — | AS13335 | Cloudflare, Inc. | 104.21.0.0/17 | — | — |
| 172.67.138.138 | 300s | — | AS13335 | Cloudflare, Inc. | 172.67.128.0/17 | — | — |
| Service | CNAME / IP |
|---|---|
| 🔷 Autodiscover | 172.67.138.138 |
| 🔶 Autoconfig | 172.67.138.138 |
| IPv6 Address | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 2606:4700:3033::6815:367e | 300s | — | AS13335 | Cloudflare, Inc. | 2606:4700:3000:0:0:0:0:0/42 | — | — |
| 2606:4700:3034::ac43:8a8a | 300s | — | AS13335 | Cloudflare, Inc. | 2606:4700:3000:0:0:0:0:0/42 | — | — |
| Priority | Target | SvcParams |
|---|---|---|
| 1 service | . | alpn="h3,h2" ipv4hint=104.21.54.126,172.67.138.138 ech=AEX+DQBBoAAgACA1APxAPIjrWnprx1OIlr9dWOcAmBlbhD5tYjQSVQgQVAAEAAEAAQASY2xvdWRmbGFyZS1lY2guY29tAAA= ipv6hint=2606:4700:3033::6815:367e,2606:4700:3034::ac43:8a8a |
| TXT Record |
|---|
| google-site-verification=4KsN3z4qfSeLt6hXVOGMESNz1IeTqY6LQFKPJdzpLas |
| v=spf1 include:_spf.google.com -all |
| Policy | Record (useful.dk) |
|---|---|
| -all (hard fail) | v=spf1 include:_spf.google.com -all |
| Policy | Record (_dmarc.useful.dk) |
|---|---|
| p=none (monitor only) | v=DMARC1; p=none; rua=mailto:85eb374f61cb4f5aa70c147c737481d3@dmarc-reports.cloudflare.net,mailto:dmarc@useful.dk |
| www | 104.21.54.126 172.67.138.138 2606:4700:3033::6815:367e 2606:4700:3034::ac43:8a8a (AS13335) (address records, no CNAME) |
| www vs bare domain | Same network |
| Wildcard | Yes: any name under the zone resolves |
| CDS / CDNSKEY | Published: key rollovers can be automated with the registry (RFC 7344/8078) 1 CDS, 1 CDNSKEY |
| Selector | CNAME | Key |
|---|---|---|
| — | RSA · ~2048 bit |
DKIM selectors can't be listed, so we check the common ones (Microsoft 365, Google, Mailchimp, SendGrid, generic). Keys under other selectors aren't shown.
DNS lookups: 1/10 · policy: -all
No problems found| Check | Result |
|---|---|
| Validation Status | 🔒 Secure |
| AD Flag (resolver validates) | ✓ Set |
| DS Record | ✓ Found |
| DNSKEY Record | ✓ Found |
| Flags | fully validated |
| Field | Value |
|---|---|
| Serial | 2417895442 |
| Primary NS (MNAME) | duke.ns.cloudflare.com |
| Responsible (RNAME) | dns@cloudflare.com |
| Refresh | 10000s |
| Retry | 2400s |
| Expire | 604800s |
| Minimum (neg-cache TTL) | 1800s |
| Field | Value |
|---|---|
| Registrar | Punktum dk A/S (direct) |
| Registered | 2003-04-23 |
| Expires | 2027-04-30 (192d) |
| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-10-19 16:58:48 shown | 529ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-10-07 01:29:34 | 6197ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-10-02 19:28:00 | 626ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-10-01 00:49:44 | 604ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-09-25 05:22:46 | 1041ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-09-04 13:23:47 | 1108ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-08-26 16:05:03 | 2081ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-08-21 19:50:47 | 1594ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-08-09 16:32:10 | 2176ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-07-15 08:20:37 | 9465ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-06-25 16:42:59 | 2419ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-06-21 04:13:03 | 1446ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-06-20 02:40:56 | 3380ms | 2 NS 2 A 5 MX | 🔒 Secure |
| 2026-06-18 07:50:41 | 946ms | 2 NS 2 A 5 MX | 🔒 Secure |